Webinars

Total Materia has allowed us to solve in a definite way all problems we had for the search of alternate materials in foreign countries. Thanks to Total Materia we have issued real "international" specs for purchase of steels in foreign countries.

Total Materia remains the only tool which will be used for this purpose.

Massimo ManfrediniBonfiglioli Industrial Gearmotors, Bologna, Italy

Our mission is simple;to make Total Materiathe one-stop place andfirst choice of engineersworld wide.

Cold Extrusion of Steel: Part One

Abstract:

Cold extrusion of metals is one of the most important manufacturing processes today and effectively involves forcing the material through the die at room temperature to create a continuous product of consistent cross-section.
Although there are minor variations, the 3 main extrusion process can be covered by forward extrusion, backward extrusion and upsetting which differ basically by the direction of the metal flow during the extrusion process.

Extrusion, though one of the most important manufacturing processes today, is a relatively young metalworking process. The cold extrusion process involves forcing a billet of material through a die at room or slightly elevated temperatures, producing a continuous product of constant cross-section. Numerous metals are suitable for cold extrusion, including lead, tin, aluminum alloys, copper, titanium, molybdenum, vanadium, and steel.

A wide variety of parts can be produced, including collapsible tubes, aluminum cans, cylinders and gear blanks. Cold extruded parts do not suffer from oxidation and often have improved mechanical properties due to severe cold working, as long as the billet temperature remains below the re-crystallization temperature.

Cold extrusion technology permits the forming of a part to the desired size and shape by moving the metal at room temperature into the die. Sufficient force is required to exceed the yield strength of the stainless steel and ensure plastic deformation results, enabling the metal to fill out the die cavities to extremely close tolerances. Although there are many different cold extrusion operations, all are variations of one or more of the following:

Forward extrusion forces the metal to flow in the same direction as the descending punch and through a hole in the die to form the required shape and dimensions, as shown in Figure 1a). Forward extrusion is especially useful in the production of bolts and screws, stepped shafts, and cylinders.

Backward extrusion forces the metal to flow upwards around the descending punch, as illustrated in Figure 1b). Extrusion pressures are generally higher and slug preparation is more critical.

Upsetting is the gathering of metal in certain sections along the length of a bar, rod or wire as shown in Figure 1c). The metal is forced to flow at right angles to the motion of the tolling. Upsetting is often performed in conjunction with backward or forward extrusions.

Physical properties are available for a huge number of materials in the Total Materia database.

Data is available through official information from standards and also through Total Materia unique similar materials cross referencing functionality, adding another dimension to your search for physical properties data!

Enter the material of interest into the quick search field. You can optionally narrow your search by specifying the country/standard of choice in the designated field and then clicking "Search".

After selecting the material of interest to you, click on the Physical Properties link to view data for the selected material. The number of physical property data records is displayed in brackets next to the link.

Physical properties are displayed according to the origin of the data set. Official data from standards can be found under the official tab, data deriving from other sources for the material will also be displayed under its own tab.

The similar materials tab displays all materials that are similar to the original material and have physical properties inserted. This can be very handy when looking for equivalent materials!

The typical tab gives a generic overview of property data for the material for you to use as a useful starting point for further investigation.